Process for improving aromaticity of heavy aromatic hydrocarbons

ABSTRACT

A process for producing paraffin extracted clarified slurry oil (raffinate) with improved aromaticity from the feed stock such as clarified slurry oil (CSO) is provided. The obtained paraffin extracted clarified slurry oil with improved aromaticity is suitable for a variety of industrial applications. For example, it can be used as a valuable feedstock for producing carbon black.

FIELD OF THE DISCLOSURE

The present disclosure relates to a process for producing raffinate withimproved aromaticity.

DEFINITIONS OF TERMS USED IN THE SPECIFICATION

The term “fluid catalytic cracking (FCC)” used in the specificationmeans the conversion process used in petroleum refineries to convert thehigh-boiling, high-molecular weight hydrocarbon fractions of petroleumcrude oils to more valuable gasoline, olefinic gases and other products.

The term “aromaticity” used in the specification means chemical propertyin which a conjugated ring of unsaturated bonds, lone pairs, or emptyorbitals exhibit a stabilization stronger than would be expected by thestabilization of conjugation. alone.

The term “raffinate” as used in the specification means paraffinextracted clarified slurry oil.

The acronym “BMCI” means Bureau of Mines Correlation Index.

BACKGROUND

Carbon black feed stock (CBFS) is a heavy hydrocarbon mix (C₂₀ to C₅₀)which is the key raw material in manufacturing carbon black. Carbonblack finds extensive use in the rubber industry as a reinforcing agentin rubber products such as tyres, tubes, conveyer belts, cables andother mechanical rubber goods. CBFS is also used as heating fuel oil inseveral industrial units. Carbon black is obtained by the partialcombustion and thermal decomposition of highly aromatic hydrocarbon oilsunder controlled conditions. Some of the most important feedstocks usedfor producing carbon black include: clarified slurry oil (CSO) obtainedfrom fluid catalytic cracking of gas oils, ethylene cracker residue fromnaphtha steam cracking and coal tar oils.

The presence of paraffins in heavy aromatic hydrocarbon fractions(boiling above 300° C.) substantially reduces their suitability forcertain applications such as production of carbon black, anode coke,needle coke, and asphaltene stabilization in delayed coker feedstock.Therefore, lower the amount of paraffins in the heavy aromatichydrocarbon fractions higher is the value of such feedstocks for theabove mentioned applications. Another important characteristic is theBureau of Mines Correlation Index (BMCI), wherein, carbon blackfeedstock must have a high BMCI to be able to offer a high yield ofcarbon black; therefore, heavy aromatic hydrocarbon feedstock used toobtain the CBFS should have a high BMCI. The BMCI is indicative of thearomaticity in aromatic hydrocarbons. Feedstocks having a high BMCI givea higher yield of carbon black with minimum heat input hence reducingthe cost of manufacturing. Also, the feedstock for carbon black shouldhave low sulfur content, as sulfur adversely affects the productquality, leads to lower yield and corrodes the equipment.

The BMCI value for CBFS should be more than 132; whereas, BMCI value ofCSO obtained at FCC plant is in the range of 110-130, typically lessthan 126, depending on the conversion in the FCC unit. Higher conversionleads to higher BMCI. Therefore, there is felt a need to increase theBMCI value of CSO above 132 before CSO can be used as a CBFS feedstockfor manufacturing Carbon Black. Further, there is also felt a need toreduce the paraffin content of CSO to enhance the applicability of thefeedstock.

In the past several processes have been worked to increase the BMCIvalue of CSO, which include:

Vacuum distillation of CSO:

Vacuum distillation of CSO separates light cycle oil (LCO) rangecomponents from CSO. Several modifications in the vacuum distillationunit such as incorporation of a CSO flasher, although helped inimproving the flash point of CSO, no improvement in the BMCI value wasobserved.

Extraction of CSO using Furfural or NMP as solvent:

Solvent extraction using NMP or Furfural was found to be unsuitable forCSO having very high aromatic content as clear separation of theraffinate and the extract was very difficult, due to the higharomaticity.

Solvent de-asphalting:

The process involves removing asphaltic material from clarified slurryoil (CSO) through the extractive or precipitant action of solvents.

Some representative patent documents which disclose solventde-asphalting process are discussed herein below.

US2002005374 discloses a process for upgrading a non-hydrotreatedfeedstream which comprises solvent deasphalting the feedstream to obtaina first product stream comprising deasphalted oil and a second productstream comprising an asphalt product; slurry hydroprocessing the asphaltproduct to obtain a hydroprocessed product; and separating an upgradedoil from the hydroprocessed product and unconverted asphaltene bottoms.

US20090166253 disclose systems and methods for processing one or morehydrocarbons for selectively separating to provide one or more lightdeasphalted oils (DAO) which can be cracked to provide hydrocarbonproducts. The method comprises: combining the feedstock comprising heavyoils, light oils, and asphaltenes with one or more solvents to provide afirst mixture; separating the asphaltenes from the first mixture toprovide a second mixture comprising solvent, heavy deasphalted oils, andlight deasphalted oils; selectively separating the heavy deasphaltedoils from the second mixture to provide a third mixture comprising thesolvent and light deasphalted oils; and selectively separating thesolvent from the third mixture to give light deasphalted oils.

US2010243518 discloses integrated slurry hydrocracking (SHC) and solventde-asphalting (SDA) methods for making slurry hydrocracking (SHC)distillates. The method involves subjecting SHC gas oil to the SDAprocess to obtain de-asphalted oil (DAO) and an SDA pitch, wherein, atleast a portion of the DAO is recycled to the SHC reaction zone.

US20090166266 discloses a method for dewatering and deasphalting a crudeoil that comprises hydrocarbons, asphaltenes and water with one or moresolvents.

The feed as employed in the presently known deasphalting processes isusually a vacuum residue or atmospheric residue or crude oil with anasphaltene content in excess of 5 wt %. It is known that the presentlyknown deasphalting process cannot be carried out if the asphaltenecontent in the input stream is lower than 5 wt %.

Another shortcoming of the known deasphalting processes is that theresidue Fraction (asphalt) as resulting from these processes is solid atroom temperature and therefore it poses significant difficulty intransportation.

Furthermore, for the presently known deasphalting processes to beeconomical the minimum limit for the DAO yield is 40% and the yieldslower than this threshold render the process economically un-feasible.

Still furthermore, the presently known deasphalting processes are silenton further value addition in the properties of the resultant deasphaltedproducts such as improved aromaticity and higher BMCI value.

Accordingly, there is felt a need for developing a new process thatextracts paraffinic material from CSO (clarified slurry oil) leading toproduce raffinate with improved aromaticity and BMCI.

OBJECTS

Some of the objects of the present disclosure, which at least oneembodiment herein satisfies, are as follows:

An object of the present disclosure is to provide a paraffin extractionprocess that is suitable for a feed with low asphaltene content such asclarified slurry oil.

Another object of the present disclosure is to provide a process forimproving the aromaticity of heavy aromatic hydrocarbons.

Still another object of the present disclosure is to provide a processfor improving the aromaticity of clarified slurry oil (CSO).

Yet another object of the present disclosure is to provide a process forreducing the paraffin content of clarified slurry oil.

Still another object of the present disclosure is to provide a processwhich gives clarified slurry oil having Bureau of Mines CorrelationIndex (BMCI) greater than 132.

A further object of the present disclosure is to provide a process forimproving the aromaticity of clarified slurry oil, which gives a usefulby-product such as extracted paraffin rich oil.

Other objects and advantages of the present disclosure will be moreapparent from the following description when read in conjunction withthe accompanying figures, which are not intended to limit the scope ofthe present disclosure.

SUMMARY

-   -   In accordance with the present disclosure there is provided a        process for producing raffinate with improved aromaticity; said        process comprising the following steps:        -   mixing CSOfeedstock having a BMCI ranging between 110 and            130 with a solvent in an apparatus to obtain an oil-solvent            mixture;        -   heating the oil-solvent mixture at a temperature ranging            between 50 and 200° C. to obtain a heated oil-solvent            mixture;        -   vigorously agitating the heated oil-solvent mixture for a            time period ranging between 0.5 and 2 hours to obtain an            oil-solvent dispersion;        -   allowing the dispersion to separate into paraffin rich phase            and raffinate phase.        -   separating the raffinate phase from the paraffin rich phase            to obtain raffinate with aromatics content of at least 90 wt            % and a BMCI of at least 132.

In accordance with another embodiment of the present disclosure theprocess further comprises heating the separated paraffin rich phase at atemperature ranging between 40 and 80° C. to remove solvent forrecycling.

Typically, the solvent is at least one selected from the groupconsisting of C₂ to C₇ hydrocarbons and C₃ to C₇ ketones.

In accordance with another embodiment of the present disclosure thesolvent is at least one selected from the group consisting of C₂ to C₇alkanes, C₂ to C₇ alkenes and C₃ to C₇ ketones.

Typically, the proportion of the solvent to oil ranges between 4:1 and10:1

Typically, the heating is carried out at a pressure ranging between 10and 50 kg/cm².

Typically, the mixing of heated oil-solvent mixture is carried out byusing a static mixer or mechanical stirrer at a temperature rangingbetween 50 to 200° C. and at a pressure ranging between 10 and 50kg/cm².

Typically, the agitation of heated oil-solvent mixture is carried out ata speed ranging between 560 to 3000 rpm to ensure proper mixing.

Typically, the pressure drops across static mixer is in the range of 1to 10 kg/cm2 (g) to ensure proper mixing.

In accordance with another aspect of the present disclosure there isprovided raffinate with aromatics content of at least 90 wt % and havinga BMCI of at least 132, obtained by the process of the presentdisclosure.

DETAILED DESCRIPTION

The embodiments herein and the various features and advantageous detailsthereof are explained with reference to the non-limiting embodiments inthe following description. Descriptions of well-known components andprocessing techniques are omitted so as to not unnecessarily obscure theembodiments herein. The examples used herein are intended merely tofacilitate an understanding of ways in which the embodiments herein maybe practiced and to further enable those of skill in the art to practicethe embodiments herein. Accordingly, the examples should not beconstrued as limiting the scope of the embodiments herein.

The description herein after, of the specific embodiments will so fullyreveal the general nature of the embodiments herein that others can, byapplying current knowledge, readily modify and/or adapt for variousapplications such specific embodiments without departing from thegeneric concept, and, therefore, such adaptations and modificationsshould and are intended to be comprehended within the meaning and rangeof equivalents of the disclosed embodiments. It is to be understood thatthe phraseology or terminology employed herein is for the purpose ofdescription and not of limitation. Therefore, while the embodimentsherein have been described in terms of preferred embodiments, thoseskilled in the art will recognize that the embodiments herein can bepracticed with modification within the spirit and scope of theembodiments as described herein.

The present disclosure envisages a novel process for producing raffinate(paraffin extracted clarified slurry oil) with improved aromaticity byextracting paraffin from feedstock such as clarified slurry oil (CSO).Further, the present disclosure also aims at reducing the paraffincontent of clarified slurry oil. The paraffin extracted clarified slurryoil (raffinate) so obtained has a high Bureau of Mining Correlation(BMCI), i.e. at least 132, which makes it suitable for applications likeraw material for carbon black production, anode coke production, needlecoke production, and as a diluent for improving asphaltene stability ofdelayed coker feedstock. The process of the present disclosure alsoprovides an extract (paraffin rich oil) which comprises approximately50-90% of the total paraffin content of the clarified slurry oilfeedstock. This by-product can be used as a feed in fluid catalyticcracking (FCC) process and hydrocracking process, as a lube oil basestock and as a thermic fluid.

The process for preparing raffinate (paraffin extracted clarified slurryoil) with improved aromaticity from clarified slurry oil in accordancewith the present disclosure is described herein below.

In the first step, clarified slurry oil feedstock having a BMCI of 110to 130 is mixed with a solvent in an apparatus to obtain an oil-solventmixture. The solvent used is at least one selected from the groupconsisting of C₂ to C₇ hydrocarbons and C₃ to C₇ ketones. In one of thepreferred embodiment the solvent used is a light hydrocarbon selectedfrom the group consisting of C₂ to C₇ alkanes and C₂ to C₇ alkenes.Typically, the structure of the hydrocarbon can be linear, branched(iso), and/or cyclic.

The clarified slurry oil is highly aromatic; thus, it is easier toseparate out the paraffins from the slurry oil on the basis of itssolubility in the light hydrocarbons, ketones or their mixtures.Depending on the process operating conditions and/or the finalapplicability of the raffinate from clarified slurry oil and theby-product i.e., paraffinic rich oil a suitable solvent or a mixture ofsolvents can be used in the process of the present disclosure forimproving the aromatic content and reducing the paraffinic content. E.g.propylene or ethylene may be added to improve the selectivity towardsthe by-product i.e. paraffinic rich oil.

The solvent to oil ratio used is typically in the range of 4:1 to 10:1.The solubilization of the solvent in the slurry oil is typically carriedout continuously in vessel or on-line which is maintained at a pressurein the range of 10-50 kg/cm² to obtain an oil-solvent mixture.

In the second step, the oil-solvent mixture is heated at a temperaturein the range of 50 to 200° C. to obtain a heated oil-solvent mixture.The process temperature can be varied depending on type of the solventand % of paraffinic oil lift required. In the next step, the heatedoil-solvent mixture is agitated vigorously for 0.5 to 2 hours whilemaintaining the temperature and pressure conditions in the autoclave.Alternatively, mechanical devices like static mixer can be used toensure intimate mixing. The agitator speed is typically in the range of500 to 3000 rpm. The obtained oil-solvent dispersion is allowed to cooland separate to obtain biphase mixture containing extract (paraffin richphase) and raffinate phase.

In the next step, the extract i.e, paraffin rich oil and the raffinatephase comprising aromatic rich slurry oil are separated.

The paraffin rich oil can be subsequently heated at a temperature in therange of 40 to 80° C. to remove solvent which is recycled as a solvent.The paraffin rich oil thus obtained comprises approximately 50 to 90 wt% of the total paraffins content of the clarified slurry oil feedstock.The paraffin rich oil thus obtained as a by-product of the process canbe suitably used as a feedstock for fluid catalytic cracking (FCC) withor without hydrotreating to subsequently obtain FCC products; afeedstock in hydrocracking process for obtaining high quality diesel andother derivative products; as a lubricating oil base stock; and as athermic fluid for heat transfer applications. The paraffin rich oilyield can be varied in the range of 15-30 wt % of clarified slurry oil(CSO) feedstock by manipulating the operating temperature between 50 and85° C. and varying solvent to oil ratio.

The raffinate phase (fraction) of clarified slurry oil obtained by theprocess of the present disclosure is characterized by aromatics contentof at least 90 wt %. i.e. the aromatic content of the raffinate fractionof clarified slurry oil is at least 5-10 wt % more than the aromaticcontent of the clarified slurry oil feedstock.

Further, the BMCI of the raffinate is found to be at least 132 which ishigher than the BMCI of clarified slurry oil feedstock.

When propane was used as a solvent, in the raffinate thus obtained, itwas observed that the aromatic content was increased by 6 wt %, the API(American Petroleum Institute) gravity was increased by 2 units, and themean boiling temperature was increased by 8° C., in comparison with theclarified slurry oil feedstock. Further, the BMCI, estimated by gravityand distillation method, was increased from 127 to 134.

The raffinate thus obtained is a valuable feedstock for processesincluding: feedstock for producing carbon black which is extensivelyused in the tyre and ink industry; feedstock for producing anode cokewhich is used in manufacturing electrodes in aluminum industries;feedstock for producing needle coke which is used in manufacturingelectrodes for high temperature applications in steel industries; and asa diluent for improving the asphaltene stability of delayed cokerfeedstock, as higher aromaticity in coker and visbreaker feed improvesthe asphaltene stability and helps to reduce the coking rates in furnacetubes thus giving an improved run length of coker.

Therefore, the process of the present disclosure, i.e., separation ofparaffin rich oil and aromatic rich raffinate by the solvent extractionof clarified shiny oil feedstock, improves the economic benefits of boththe products (raffinate) and the by-product (paraffin rich oil), bymaking them more suitable for a variety of industrial applications.

The disclosure will now be described with respect to the followingexamples and illustrations which do not limit the scope and ambit of thedisclosure in anyway and only exemplify the disclosure.

EXAMPLE

55 gms of clarified slurry oil (CSO) feedstock was mixed with propane,in a propane to oil ratio of 6:1, in an autoclave. The oil-solventmixture was heated to 85° C. at a pressure of 33 kg/cm² and theresultant mixture was stirred for one hour at 1000 rpm while maintainingthe temperature and pressure conditions. The stirring and heating wasstopped and the resultant dispersion was allowed to settle under gravityfor one hour, thus allowing the separation of a paraffin rich phase(extract) and a aromatic rich phase (raffinate) which is a heavierfraction. The paraffin rich phase (extract) was decanted out from thetop and was separately heated to 50° C. to remove propane. The samplesof the paraffin rich phase (extract) were tested in Advanced CrackingEvaluation (ACE) reactor for crack-ability. The aromatic rich phase(raffinate) was subsequently obtained after decanting. The extract andraffinate were analyzed for viscosity, density, High TemperatureSimulated Distillation and SARA (Saturates, Asphaltenes, Resins andAromatics) analysis. The SARA analysis was done using TLC-FID analyzer.The properties of clarified slurry oil feedstock, raffinate and extractare illustrated in TABLE 1.

TABLE 1 Properties of clarified slurry oil feedstock (CSO), raffinateand extract Specification for use as carbon black feedstock Units CSORaffinate Extract CBFS Average Yield wt % 100 82 18 — (for 3 consecu-tive runs) Specific gravity — 1.0836 1.10 1.01 Maximum 1.10 at 15° C.API gravity — −0.917 −2.86 8.60 Maximum −2.9 BMCI (by — 127 134 94.65Minimum 132 gravity & distillation method) Sulfur Content wt % 1.4581.65 0.278 Maximum 3 Saturates wt % 11.65 4.94 31.93 — Aromatics wt %85.83 91.69 66.51 — Asphaltenes wt % 0.47 0.78 0.16 Maximum 6 Catalystwt % 12.52 15.25 0.07 — Regeneration Reformers (CCR)

The data reported in the TABLE 1 is for samples having 18 wt % paraffinrich oil (Extract) and 82% aromatic rich phase (raffinate). The datapresented is for a typical set of properties and not to be considered aslimiting in any way the process as such.

The BMCI was calculated using the following equation:

BMCI=(48640/T)+(473.7*specific gravity)−456.8

where, T(° K)=273+(T₁₀+T₃₀+T₅₀₊T₇₀+T₉₀)/5

It was observed that the aromatic content of the raffinate was 6 wt %higher than the clarified slurry oil (CSO) feedstock. Further, thecorresponding API gravity of raffinate was increased by 2 units and theBMCI value calculated by gravity and distillation method was increasedfrom 127 to 134, in comparison with the feedstock. A higher density andlower average boiling point is desired for improving the BMCI. Stillfurther, the propane extraction process removed more than 50% ofsaturates from the feedstock, as, in the raffinate obtained. Theexperiment was carried out in a single-stage mixer settler lab autoclaveunit. The extract yield and its saturate content are expected to improvefurther in a continuous multi-stage extraction process having specialinternals for better mixing and settling. The extract obtained by theextraction process of the present disclosure has low Conradson CarbonResidue (CCR) and Asphaltenes content, which makes the extract suitableas a FCC feed with or without hydrotreating, as a hydrocracker feed, aslube oil base stock, and as thermic fluid for heat transferapplications.

The clarified slurry oil feedstock (CSO), raffinate and extract wereanalyzed in a gas chromatograph (High temperature Simdist, D7169). Theanalysis is illustrated in TABLE 2.

TABLE 2 High temperature Simdist temperature analysis of clarifiedslurry oil feedstock (CSO), raffinate and extract Temperature (° C.)Recovered Mass % CSO Raffinate Extract Initial Boiling Point (IBP) 223229 148.5  5 313.5 320 265 10 345 347 311.5 20 363.5 365.6 352.5 30 378380.5 368.5 50 406 409 395 70 440 447 421.5 80 467 476 439.5 90 517 542469.5 95 582.5 601.5 493.5 Final Boiling Point (FBP) 693 696 617.5 T =(T₁₀ + T₃₀ + 417.2 425.1 393.2 T₅₀ + T₇₀ + T₉₀)/5

Further, the crack-ability of extract was studied in an ACE reactor; thedata was generated at base conditions of 545° C. and compared withcorresponding conversion selectivity plots of hydrotreated vacuum gasoil (VGO) feedstock. The extract showed a much lower conversion thanhydrotreated (DDT) VGO, 40-45 wt % vis-à-vis 70-80 wt %, at differentcatalyst to oil ratio. This is consistent with higher aromatics contentof extract and reflected in lower UOP K. Higher aromatics also result inhigher coke make. Since, the CCR and Asphaltenes content of extract arewithin the limits of hydrotreater feed requirement, it is possible toprocess the extract in hydrotreater for aromatics saturation and UOP Kimprovement. KBC VGO-HT Kinetic model estimates showed aromaticssaturation in extract from 65% to 50% by wt and UOPK factor improvementfrom 10.4 to 10.7. Extract as such shows a conversion of approximately41 wt % (at 216° C.) and approximately 66 wt % (at 370° C.).Hydrotreating improves the conversion to approximately 47 wt % (at 216°C.) and approximately 77 wt % (at 370° C.). This shows substantialpotential for upgrading the extract through VGO-HT and FCC. TABLE 3illustrates yields estimates of products of extract and hydrotreated(HDT) extract in FCC by KBC Simulation Kinetic model.

TABLE 3 Yield of products by cracking extract obtained by process of thepresent disclosure in FCC Base & 100% Base & HDT 100% HDT Product UnitBase Extract Extract Extract Extract Dry Gas wt % 5.01 4.98 4.96 3.131.72 Propylene wt % 9.50 9.44 9.46 5.47 6.97 Total wt % 20.24 20.0820.13 9.07 12.62 C₃ + C₄ Total Naphtha wt % 37.32 37.05 37.10 18.6722.20 Light Cycle Oil wt % 15.11 15.24 15.19 24.21 20.41 Clarified Oilwt % 7.50 7.89 7.85 34.15 30.68 Coke wt % 5.32 5.32 5.32 5.30 5.39Conversion wt % 77.39 76.87 76.96 41.65 47.33 Total 100 100 100 100 100

Technical Advantages

A process for improving the aromaticity of heavy aromatic hydrocarbonsas described in the present disclosure has several technical advantagesincluding but not limited to the realization of

-   -   the aromatic content of clarified slurry oil feedstock can be        increased by 5-10 wt. %;    -   the BMCI of paraffin extracted clarified slurry oil (raffinate)        is at least 132;    -   the paraffin content of raffinate is substantially reduced;    -   the API gravity of raffinate is increased; and    -   the applicability and thus the economic benefit of the raffinate        and extract are improved.

Throughout this specification the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated element, integer or step, or group of elements, integers orsteps, but not the exclusion of any other element, integer or step, orgroup of elements, integers or steps.

The use of the expression “at least” or “at least one” suggests the useof one or more elements or ingredients or quantities, as the use may bein the embodiment of the disclosure to achieve one or more of thedesired objects or results.

Any discussion of documents, acts, materials, devices, articles or thelike that has been included in this specification is solely for thepurpose of providing a context for the disclosure. It is not to be takenas an admission that any or all of these matters form part of the priorart base or were common general knowledge in the field relevant to thedisclosure as it existed anywhere before the priority date of thisapplication.

The numerical values mentioned for the various physical parameters,dimensions or quantities are only approximations and it is envisagedthat the values higher/lower than the numerical values assigned to theparameters, dimensions or quantities fall within the scope of thedisclosure, unless there is a statement in the specification specific tothe contrary.

1. A process for producing raffinate with improved aromaticity; saidprocess comprising the following steps: a. mixing raffinate feedstockhaving a BMCI ranging between 110 and 130 with a solvent in an apparatusto obtain an oil-solvent mixture; b. heating the oil-solvent mixture ata temperature ranging between 50 and 200° C. to obtain a heatedoil-solvent mixture; c. vigorously agitating the heated oil-solventmixture for a time period ranging between 0.5 and 2 hours to obtain anoil-solvent dispersion; d. allowing the dispersion to separate intoparaffin rich phase and raffinate phase; e. separating the raffinatephase from the paraffin rich phase to obtain raffinate with aromaticscontent of at least 90 wt % and a BMCI of at least
 132. 2. The processas claimed in claim 1, further comprises heating the separated paraffinrich phase at a temperature ranging between 40 and 80° C. to removesolvent.
 3. The process as claimed in claim 1, wherein the solvent is atleast one selected from the group consisting of C₂ to C₇ hydrocarbonsand C₃ to C₇ ketones.
 4. The process as claimed in claim 1, wherein thesolvent is at least one selected from the group consisting of C₂ to C₇alkanes, C₂ to C₇ alkenes and C₃ to C₇ ketones.
 5. The process asclaimed in claim 1, wherein the proportion of the solvent to oil rangesbetween 4:1 and 10:1.
 6. The process as claimed in claim 1, wherein theheating is carried out at a pressure ranging between 10 and 50 kg/cm².7. The process as claimed in claim 1, wherein the agitation of heatedoil-solvent mixture is carried out at a temperature ranging between 50and 200° C. and at a pressure ranging between 10 and 50 kg/cm².
 8. Theprocess as claimed in claim 1, wherein the agitation of heatedoil-solvent mixture is carried out at a speed ranging between 500 and3000 rpm.
 9. The process as claimed in claim 1, wherein the step c iscarried out in a static mixer.
 10. Raffinate with aromatics content ofat least 90 wt % and having a BMCI of at least 132, obtained by theprocess as claimed in claim 1.